Sight opening for oil burning furnaces



Oct. 17, 1933- c. L. WARNER SIGHT OPENING FOR- OIL BURNING FURNACES Filed July 15, 19:52

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Patented Oct. 17, 1933 UNITED STATES PATENT orrice SIGHT OPENING FOR/OIL BURNING FURNACES Charles L. Warner, Milford, Conn., assignor to Baird-Warner, Incorporated, Bridgeport, Conn., a corporation of Connecticut Application July 15, 1932. Serial No. 622,586

6 Claims.

This invention relates to new and useful improvements in peep or sight openings and has particular relation to a peep or sight opening for furnaces which have been changed from coal burning to oil burning furnaces.

When a coal burning furnace is converted into an oil burner it is very desirable that some means be provided whereby the flame of the oil burner may be viewed in order thatit may be regulated. Of course, the flame may be viewed on opening of the furnace door but such procedure admits cold air to the furnace so that conditions in the combustion chamber are changed and a view of the flame produced when the door is closed and under the conditions of normal operation cannot be had.

An object of the present invention is to provide a peep or sight opening which may be applied to a door of a furnace at the furnace or that is on the job without requiring that the door be carried to the shop or that special tools be provided and irrespective of the shape or contour of the furnace door, and through which the flame within the furnace may be viewed without opening the furnace door and therefore under normal operating conditions.

Other objects and advantages will become apparent from a consideration of the following detailed description taken in connection with the accompanying drawing whereinembodiments of the invention are shown. However, it will be understood that the invention is not limited to the details disclosed but includes all such variations and modifications as fall Within the spirit of the invention and the scope of the appended claims.

In the drawing:

Fig. l is a front elevational view of a portion of a furnace the door of which is shown closed and equipped with a sight opening in accordance with the invention; a I

Fig. 2 is a view similar to Fig. 1, the furnace door being shown open;

Fig. 3 is a detail-sectional view taken substan tially along the linev 3-3 of Fig'. 1 and on anenlarged scale; 1

Fig. 4 is a sectional detail on a further enlarged scale;

Fig. 5 is a rear elevational view of the device detached; and

Fig. 6 is a view similar to Fig. 4 but showing a slightly modified structure.

Referring in detail to the drawing and at first particularly to Figs. 1 through 5 thereof at 10 is shown a portion of .a furnace including a door 11 hingedly mounted as at 12. The central portion 13 of the door maybe outwardly off-set as shown or the entire front face of the door may be in the same plane. Generally, these doors are 'of cast iron and have the manufacturers name cast therein whereby the doors are'of irregular contour. They also usually have a curved or offset portion. When a furnace as for example the furnace 10 has been changed from a coal burner to an oil burner considerable difficulty has been experienced in providing a sight opening through which the flame of the oil burner may be viewed under actual working conditions. According to-the present invention means are provided whereby a furnace door, irrespective of its contour, may be'easily and quickly equipped with a sight opening. The invention provides a sight opening structure which a mechanic may carry with him and after he has arrived on the job mount in a furnace door. This means includes a frame generally designated 14'and including a hollow open ended body portion 15 at its inner end provided with an annular extension orflange 16 the edge portion of which is turned forwardly as at 17 fora purpose tobe described. The forward portion of the body 15 is inturned providing a marginal flange 18 and against this flange 18 there isdisposed a sightglass 19. The frame is preferably stamped and formed from sheet metal 7 of proper thickness.

A groove 20 is rolled into the body 15'intermediate its ends and the rolling of this groove provides a bead 21 at the inner side of the body inwardly of the sight glass 19. Between this bead 21 and the glass there is disposed a split spring ring 22 which serves to retain the glass against the flange 18 and which in turn is held in place by the bead 21. The flange 16 is provided with two or more openings through which are passed bolts 23 equipped with nuts 24 and adapted for securing the frame 14 to the door '11. v ,f

Whenan oil burner is installed in the furnace 10 an opening 25 is out in the furnace door I and smaller openings are drilled at the sides of the opening 25, the smaller openings being de-' signed to receive the bolts 23. The opening .25 may be cut in the door at any convenient place or point and if desired without removing the door from the furnace. Next, the flange 16 is filled with furnace cement as at 26 and the frame is 1 placed in position at the inner side of thevdoor .with the central body portion 15of the frame in the opening 25 in the door, and while the cement is soft so that it can shape itself to the contour of the surface of the door and make a no tight fit. The boltsare then passed through the door, and the nuts 24 tightened. to secure the frame in place after which the cement is permitted to harden.

The opening may be cut by tools carried in the usual kit. Thus a guide hole of relatively small diameter may be drilled with a hand drill at the center of the location for the opening and then a tool comprising a central guide pin or stud to enter this hole and having a circular cutter similar to a hack saw blade held in the form of a circle used to cut the opening to the larger size required. This can be done on the job without carrying the door to the shop.

When the door is of irregular contour as shown additional cement is used to fill in the space between the flange l6and any offset portions of the door this being illustrated at 2'7 in the lower portion of Fig. 3. It will be noted that the opening 25 through the door is effectively sealed by the cement under the flange l6 and should this cement crack it will be held in place by the forwardly turned portion 17 of the flange 16 and prevented from falling out of place.

In Fig. 6 the parts are as heretofore described with the exception that the body 15 is provided with a corrugated flange 28, in lieu of the flange 16 above referred to, and as the cement 26 is applied in a softened'or plastic condition it will be appreciated that the cement will be held in place by this corrugated flange should the cement crack on hardening or at any time. That is, the cement as applied will, of course, fill in the corrugations in the flange 28. It will further be noted that the extreme edge portion 29 of said flange 23 is turned forwardly whereby to somewhat overlap the edge of the cement 26.

With either form of theinvention after the frame is applied andthe nuts 24 tightened on the bolts 23 surplus cement about the edge of the inside flanges may be wiped away to give the device a finished appearance. Since the cement is applied in its softened condition the device of the invention may be applied to almost any part of a furnace door even though the door be curved or provided with lettering. This is true since the cement will fill the space between the inner flangeof the device and the door and will enter into any depressions or irregularities and provide an effective seal.

With the device in place in a furnace door it will be apparent that any one looking through the glass 19 will be in a position to observe the flame within the furnace without opening the furnace door. Therefore,-the flame may be viewed under actual working conditions and anydesired or necessary adjustments made. Further, it should be appreciated that the device of the present invention is of relatively simple construction so'that it may be made at low cost. Also, thedevice is of's'uch construction that a mechanic'not having previously viewed a job may take a frame 14 with him to the job and there install it'in' a furnace door irrespective of the con- 'tour of said door. Withthe present device it is not necessary to have a special construction of sight for each different furnace door.

Having thus set forth the nature of. my invention, what I claim is: V a .1. In asightopening for a furnace door, a frame including an open ended hollow body to be disposed inan opening in a furn ace door, a

flange at one end of said body and extending laterally thereof to engage a surface of the furnace door and adapted to hold a plastic sealing material, a sight glass in said body and closing one end thereof, said sight glass mounted in and carried by said body and formingtherewith a unit, and means to clamp a portion of said flange against a surface of the furnace door to secure the said unit in place on the door.

2. In combination, a furnace door having an opening therethrough, a frame including a hollow open ended bodyportion registering with said opening, a laterally extending flange on said body portion, means sealing the space between said flange and the door about the opening in the latter, means passing through the flange and the door and securing the frame to the door, a sight'glass. in said body and closing the same, and an independent means securing said sight glass in the body whereby the sight glass and body form a unit to be mounted in the door.

3. In combination, a furnace door having an opening therethrough,-a frame including a hollow open ended body portion registering with said opening, a laterally extending flange on said body portion, means. sealing the space between said flange and the door about the opening in the latter, means engaging said flange andsecuring the frame to the door, a sight glass in said body and closing the same, and an independent means securing said sight glass in the body whereby the sight glass and body. form aunit to be mounted in the door. I a

i. In combination, a furnace door having an opening therethrough, a frame including a hollow open ended body portion disposed in said opening, a laterally extending flange on said body at the inner side of the furnace door, means sealing the space between said flange and the door about the opening in,-the latter, said flange having its outer edge portion bent to embrace the outer edge portion of said sealing means to retain it in place, means securing said frame to the door, a sight glass, in said body and closing one end thereof, and means securing the sight glass 1 in the body whereby the glass and body form a unit and are mounted as such in the door'opening.

'5. In combination, a' furnace door having an opening therethrough, a frame including a hollow open ended body portion ing in the furnace door, a laterally extending flange on said body portion at the inner side of the furnace door, seaiing means in the space between said flange and the door about the opening in the latter, said sealing means comprising a hardened plastic cement, said flange corrugated to retain said cement in place, means securing disposed in said open- 1 n is the frame to the furnace door, and a sight glass 7 in and supported entirely bysaid body and closing the outer end thereof.

6'. In a sight opening frame including an open ended hollow body to be disposed in an opening. in a furnace door, an outwardly directed flange atone end of said body, an inwardly directed flange at the other end of said'body, a sight glass within said body and against said inwardly directed flange, a bead in said body inwardly of said sight glass, and a split spring ring within said body and between said head and sight glass and securing said glass against the inturned flange.

' CHARLES L. WARNER.

. I 1 for a furnace door, a 

